This was my first experience reading a Hannibal book, and that's mostly due to the fact that serial killers with motivations, Hannibal included, do not usually scare me. I've also seen the movies, which I enjoyed, but they didn't drive me out to read the books. Despite my tardiness in reading any of this collection, I have to say, the story builds and handles tension terrifically, making Red Dragon a fine example to analyze for developing such skills. The majority of the tension wasn't created with horror or gore, either; the tension came from character interactions, and mainly from Hannibal, Graham, and Dolarhyde/the Dragon.
Hannibal and Graham are my favorites, so they'll be first. Graham considers himself, along with most of the world, to be psychotic. He's faced traumatic events, which have injured his perception of life, and he is now able to get into the minds of serial killers. So, he's a good guy, bordering on the darkness. Hannibal mirrors his darkness, and through the book you see Graham struggle with the darkness and the light inside himself, which is represented by his family. Hannibal loves Graham for the similarities they share. He is in awe of Graham for catching him; however, Hannibal also hates Graham for catching him. There's also tension between the two due to the coincidental events that led Graham to reveal Hannibal as a murderer: Graham did not outsmart Hannibal, only got lucky by connecting a few clues.
Hannibal and the Tooth Fairy interacted very little, but their correlation should be mentioned. I call the Dragon by the name Tooth Fairy here because when he communicated with Hannibal, he was known by that name. And since little was known about him at that time, the reader is left unsure which persona wrote the toilet-paper letter--the Dragon or Dolarhyde. Anyway, Hannibal appreciates the Tooth Fairy's accolades, but I also got the feeling he held himself higher than the Tooth Fairy, considers the Tooth Fairy to be lesser of a person and a killer. Tension is also created as their very interaction was prohibited, written on toilet paper and then via personal ads. To top it off, when the police found out about the communication, a second level of tension was added because the police covered up the fact they knew of the correspondence. They then played on it in an attempt to catch the Tooth Fairy, who then proclaims himself to be the Dragon.
The Dragon and Dolarhyde are essentially the same character for Graham. He's hunting one killer and that killer bites back. When the killer strikes back, essentially both the Dragon and Dolarhyde are releasing their anger of the world on Graham because they both hate him. When Freddy Lounds is tortured and set ablaze, the Dragon and Dolarhyde do so to taunt Graham. In the end, their goal becomes Graham and his family. In this book, these two characters become the two kings on the chess board, playing games to trap eachother. The tension for the rest of the tale spirals from their interactions.
Dolarhyde and the Dragon are important to distinguish because their goals do not always align. The Dragon wants to kill, and Dolarhyde wants to become the Dragon. Dolarhyde tries to control the Dragon by ingesting the artwork of the beast and does so because his goal becomes living a normal life with Reba McClane. When this dream collapses, his goals shift to those of the Dragon; in other words, Dolarhyde fails to achieve his goal and becomes the Dragon. Since the differentiation of their goals is whether Reba McClane lives or dies, the tension between these two characters is the greatest for me as the stakes are the most real, brought the most to life, in the story--the fate of McClane’s life depended on how Dolarhyde and the Dragon interacted.
So, those are the main characters of Hannibal and how they interact with each other to cram this book full of tension. They, of course, interact with secondary characters to build a three-dimensional story, but it is still the interactions between Hannibal, Graham, and Dolarhyde/the Dragon who make this story so exciting and fascinating.